Dynamic frequency planning in shared spectrum

ABSTRACT

Dynamic frequency planning of shared spectrum is contemplated. The sharing may facilitate use of unlicensed or non-exclusively licensed spectrum within a geographical area service by two or more spectrum access sharing systems (SASs) or otherwise subjected to control of independently operating entities.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application No.62/452,043 filed Jan. 30, 2017, the disclosure of which is incorporatedin its entirety by reference herein.

TECHNICAL FIELD

The present invention relates to dynamic frequency planning of sharedspectrum, such as but not necessarily limited to facilitating use ofunlicensed or non-exclusively licensed spectrum within a geographicalarea service by two or more spectrum access sharing systems (SASs).

BACKGROUND

New non-exclusively licensed shared spectrum paradigms mean thatfrequency plans need to work across independent network operators.Certain operators may have higher priority than others, which hasimplications for frequency plans. Mobile incumbents or priority networksmay appear or move within the area, forcing dynamic frequency planningupdates. Different networks in these bands, such as LTE-TDD and 3GPPLAA, will need either guard bands between networks to reduceinterference, or they will need a central frequency plan coordinationacross operators to reduce guard bands. Since guard bands areinefficient, central coordination is preferred. What is needed iscentralized method to dynamically optimize inter-operator frequencyplans in shared spectrum.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a diagram for facilitating frequency sharing ofnon-exclusively licensed spectrum in accordance with one non-limitingaspect of the present invention.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The FIGURES are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

FIG. 1 illustrates a system 10 for facilitating frequency sharing ofnon-exclusively licensed spectrum in accordance with one non-limitingaspect of the present invention. While applicable to other environmentsutilizing other bands of unlicensed or shared spectrum, the system 10may be configured to facilitate implementing wireless signaling suitablycompliant with the Citizens Broadband Radio Service for shared wirelessbroadband use of the 3550-3700 MHz band (3.5 GHz Band) as adopted by theU.S. Federal Communications Commission (FCC). The Citizens BroadbandRadio Service is governed by a three-tiered spectrum authorizationframework to accommodate a variety of commercial uses on a shared basiswith incumbent federal and non-federal users of the band.

Incumbent Access users include authorized federal and grandfatheredFixed Satellite Service users operating in the 3.5 GHz Band. These userswill be protected from harmful interference from Priority Access andGeneral Authorized Access users. The Priority Access tier consists ofPriority Access Licenses (PALs) that will be assigned using competitivebidding within the 3550-3650 MHz portion of the band. Each PAL isdefined as a non-renewable authorization to use a 10 megahertz channelin a single census tract. The General Authorized Access (GAA) tier islicensed-by-rule to permit open, flexible access to the band for thewidest possible group of potential users. GAA users are permitted to useany portion of the 3550-3700 MHz band not assigned to a higher tier userand may also operate opportunistically on unused Priority Accesschannels.

One non-limiting aspect of the present invention contemplatesfacilitating dynamic frequency sharing between a first spectrum accesssharing system (SAS) 12 and a second SAS 14. The first and second SASs12, 14 or other suitable controllers may be responsible forindependently and respectively controlling a first plurality of accesspoints (APs—shown with towers) 16 and a second plurality of APs 18. Thefirst and second APs 16, 18 may be co-located or otherwise positionedwithin relative proximity such that unlicensed or shared spectrumwireless signaling associated therewith (shown with hexagons) overlapssuch that a user device (not shown) within either one of a first networkassociated with the first plurality of APs 16 and a second networkassociated with the second plurality of APs 18 may receive wirelesssignals associated with both of the first and second networks. The SASs12, 14 may include a non-transitory computer-readable medium having aplurality of instructions executable with an associated processor tofacilitate sharing the unlicensed spectrum available to the first andsecond APs 16, 18.

The sharing of spectrum, particularly unlicensed spectrum or othersignaling being commonly shared across independently controlledentities, e.g., within the 3.5-3.7 GHz range or 3.5 GHz band, isbelieved to be beneficial in avoiding interferences and/or othersignaling degradations when multiple APs 16, 18 may be attempting tocontemporaneously use the unlicensed or shared spectrum within a commongeographical area. The sharing of frequency/spectrum may be facilitatedwith optimization matrices (shown as squares) and/or related data beingshared between the SASs 12, 14 for purposes of determining an optimizedusage of the shared spectrum across all users, e.g., incumbent users,PAL users and GAA users. The optimization matrices may be files,extensible markup language (XML) schema, documents or other constructssufficient for communicating information between the SASs 12, 14. TheSASs 12, 14 may analyze the matrices being exchanged to determine anoptimized set of operating characteristics and parameters for the firstand second APs 16, 18 or additional APs within the control thereof orcontrol of another SAS so as to maximize access, usage, throughput,quality of service (QoS) or other features of the first and secondnetworks through coordinated usage of shared spectrum, which mayoptionally be performed in a manner that equally favors all users withinthe three-tiered hierarchy.

The SASs 12, 14 may be configured to generate, share and processoptimization matrices having entries sufficient for reflectingcharacteristics of the APs 16, 18 associated therewith, which mayinclude representing one or more of the following: path loss;interference levels; mutual coupling between directional antennas;available channels at the APs 16, 18; technology standard deployed ateach AP 16, 18; and/or location of the APs 16, 18. The SASs 12, 14 maythen use this and/or other information shared or known to cooperativelynegotiate frequency/channel assignment, time domain duplex (TDD) frameconfiguration, transmit power, beamforming and/or other capabilities ofthe APs 16, 18 to form a shared matrix or complete set of matricesencompassing all APs 16, 18 and settings for each. The SASs 12, 14 maynegotiate in this manner to achieve the most bits transmitted in ageographic area with suitable constraints to accommodate incumbents andhigher priority networks and/or to achieve other desired operatingstates for some or all of the geographical areas subject to sharedspectrum overlap. The shared matrix and/or the complete set of optimizedmatrices may be dynamically updated for: mobile incumbents; basestations that enter or leave the area; changes in propagation conditionsaffecting path loss between base stations.

The informational exchange between the SASs 12, 14 may include: aprocess 20 where the first SAS 12 proposes an initial optimizationmatrix for the first network; a process 22 where the second SAS 14proposes an update to the initial optimization matrix according topreferences/needs of the second SAS along with an expanded matrix forthe second network; and a process 24 where the first and second SASs 12,14 then negotiate converged entries, i.e., merging or integrating theexchanged matrices to create the shared matrix or complete set ofmatrices optimized according to an agreed upon performance metric forthe first and second networks individually and/or in totality, i.e.,overall performance when viewed from a combined operation point of view.Each of the SASs 12, 14 may then execute processes 26, 28 associatedwith updating and/or otherwise configuring the associated APs 16, 18according the shared matrix, such as by configuring the PHY parameters,e.g., frequency or frequencies to be used at each AP 16, 18, for thefirst and second networks through suitable instructions and commands.

The SASs 12, 14 may share information in the contemplated manner tofacilitate: use of a centrally coordinated optimization platform acrossmultiple independent mobile network; use of an optimization matrix orset of optimization matrices to represent a set of independent networkbase stations; optimization matrix entries and algorithms with weightsthat reflect priority users and priority user protection zones; acentralized optimization coordinator to update the PHY parameters ofmultiple independent networks for overall increased capacity andperformance in the shared spectrum area; dynamically updating the sharedmatrix as incumbent events are detected, base stations are added ordeleted and/or as propagation condition changes are detected betweenAPs; frequency planning across multiple independent networks withfrequency reuse >1; frequency planning across multiple independentnetworks with frequency reuse=1, including joint use of LTE ICIC acrossindependent networks in an optimized plan; the ability for multiple SASsto negotiate a single optimized matrix or set of matrices that representthe superset of networks in each area of each SAS where each SAS canpropose a partial matrix solution that reflects their networks withtheir view of their optimization for their networks and/or each SAS canrespond with a more complete matrix that adds entries for its networkswith its preferred optimization solution; superset optimization updatesmay be proposed by the SAS or SASs that detect an incumbent event;and/or superset optimization updates are proposed by the SAS thatdetects a base station being added or deleted from any the networks.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

What is claimed is:
 1. A method for dynamic frequency planning of sharedspectrum, the shared spectrum being utilized by a plurality of accesspoints (APs) within an overlapping geographical area to facilitatewireless signaling, a first plurality of the plurality of APs beingcontrolled with a first spectrum access sharing system (SAS) and asecond plurality of the plurality of APs being controlled with a secondSAS, the method comprising: transmitting a first optimization matrixfrom the first SAS to the second SAS, the first optimization matrixrepresenting operating characteristics for the first plurality of APs;receiving an updated optimization matrix and a second optimizationmatrix from the second SAS, the update optimization matrix includingproposed changes to the first optimization matrix, the secondoptimization matrix representing operating characteristics for thesecond plurality of APs; and negotiating between the first SAS and thesecond SAS based on the first, second and updated optimization matricesto converge each into a shared matrix, the shared matrix sufficient forthe first SAS and the second SAS to set physical layer (PHY) parametersassociated with frequency usage within the shared spectrum for the firstand second APs controlled thereby.